Spin Response in Organic Spin-Valves based on LSMO Electrodes

ORAL

Abstract

We fabricated spin-valves made of organic semiconductor (OSEC) thin films sandwiched between ferromagnetic La$_{2/3}$Sr$_{1/3}$MnO$_{3}$ (LSMO) and cobalt electrodes, using several OSEC small molecules. We measured the temperature (T) and voltage bias (V) dependence of the spin-valve related giant magneto-resistance (GMR) effect. We found a universal GMR decrease with T, where the GMR completely diminishes at $\sim $ 250K regardless of the OSEC layer. We show evidence that the underlying mechanism for the GMR decrease with T is the decrease in the spin injection capability of the LSMO electrode. We also found that the GMR steeply decreases with V, and is asymmetric respect to the applied voltage direction.

*Supported in part by grants from the DOE and the NSF DMR at the University of Utah.

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Authors

  • Fujian Wang

    • Department of Physics, University of Utah

  • Cungeng Yang

    • University of Utah
    • Department of Physics, University of Utah

  • Valy Vardeny

    • Physics Dept., University of Utah
    • University of Utah
    • Department of Physics. University of Utah
    • University of Utah, Department of Physics, Salt Lake City, Utah 84112
    • Physics Department, University of Utah

  • Xiaoguang Li

    • Hefei National Laboratory for Physics Sciences at Microscale and Department of Materials Science \& Eng, University of Science and Technology of China